Filter



FIG. 1 is a top perspective view of a filter;

FIG. 2 is a bottom perspective view of the filter;

FIG. 3 is a front view of the filter;

FIG. 4 is a back view of the filter;

FIG. 5 is a top view of the filter;

FIG. 6 is a bottom view of the filter;

FIG. 7 is a right side view thereof rotated rightward; and,

FIG. 8 is a second right view rotated leftward.

The broken lines in the figures depict portions of the filter that form no part of the claimed design. The dot dash dot broken lines denote the boundaries of the claim and form no part thereof. 

CLAIM The ornamental design for a filter, as shown and described. 